Das Projekt "Projekt Endlagerstaettengruppe - eine Grundlage fuer die Bewertung und Entwicklung von Konzepten fuer Endlagerstaetten fuer hochradioaktive Abfaelle" wird vom Umweltbundesamt gefördert und von Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH - Fachbereich Endlagersicherheitsforschung durchgeführt. For technical/economical optimisation of concepts of future European repositories for rad waste it would be of great help if assessment is made of the experience from the various large-scale underground laboratories for testing techniques and which specifically aims at comparing methods and data obtained from the laboratories for evaluating present concepts and developing improved ones. Several of these underground projects, which deal with disposal in crystalline rock, salt and clay formations, have been supported by the EC. The proposal implies constitution of a forum -a cluster- for the intended evaluation and assessment, focusing on construction, instrumentation and correlation of theoretical models with field data, especially concerning EBS.